Natural gas extracted from the ground typically includes a number of impurities and contaminants that are carried with the gas, such as water, oil, liquid hydrocarbons, solids, drilling mud, sulfur compounds, and others. Natural gas is typically decontaminated, dehydrated, and otherwise processed prior to being sold by consumers. An important part of the processing of natural gas is the removal of water from the natural gas because water can cause gas line clogging and bursting when the water is trapped in the gas line and freezes due to cold weather, for example.
A number of systems exist for dehydrating natural gas to remove water and other liquids from the natural gas. Most of these dehydration systems involve passing natural gas through, or contacting natural gas with, one of a number of known desiccant fluids, such as tri-ethylene glycol. Desiccant fluids essentially dissolve or otherwise absorb water, liquid hydrocarbons, and other liquids and contaminants from natural gas. The dehydrated natural gas is discharged from the dehydration system for use or as sales gas, and the “wet” desiccant fluids are typically recycled through the dehydration system to be regenerated (or returned to a “dry” state) and reused to dehydrate natural gas.
One of the steps of recycling wet desiccant fluids may include processing wet desiccant fluids with a three-phase separator, known as a flash separator, to separate gas and hydrocarbon liquids from the wet desiccant fluid. Several prior art three-phase glycol separators have been suggested. However, such separators rely on float level controllers and motor valves to control the levels of glycol inside the separator. Such float level-controllers and motor valves are complicated to use, require constant adjustments in the field, and are inherently unreliable and known to cause frequent malfunctions and delays. Further, the efficiency of separation of the float level-controlled prior art devices is largely dependent on operator skill and training, which coupled with the frequent need of adjusting the float level controllers and motor valves, results in inconsistent separation, shortened life of the desiccant fluids, and gas dehydration process inefficiencies.